1. Field of the Invention
The present invention relates to a textured substrate applied to a thin film formation surface in a textured substrate for epitaxial film formation. More in detail, the invention relates to a textured substrate further improved in crystal orientation and surface smoothness.
2. Description of the Related Art
In recent years, the material whose specific property an epitaxial crystal structure has is focused on has been used in various fields. Its typical examples include a superconducting conductor applied to a variety of power equipment and an oxide superconducting material constituting a superconducting shield and the like. The material having this epitaxial crystal structure is generally poor in workability, and is disadvantageous in cost when manufacturing a bulk material, and for this reason, it is often used in the form of its thin film on a predetermined substrate.
Since a substrate for epitaxial film formation allows an epitaxial crystal having an orientation structure to grow, its surface also is required to have an orientation structure. As such substrate, a textured substrate made of copper, silver, nickel or alloy of these metals and the like, and including a textured metal layer having a biaxially textured {100}<100>cube texture is used (for example, “Biaxially textured copper and copper-iron alloy substrates for use in YBa[2]Cu[3]0[7][−][×]” (Superconductor science and technology ISSN0953-2048, 2006, vol.19, pp.85-95), “Control of texture in Ag and Ag-alloy substrates for superconducting tapes” by T A Gladstone, JC Moore, B M Henry, S Speller, C J Salter, A JWilkinson and C R M Grovenor, Department of Materials, University of Oxford, Supecond, Sci. Techno. 13(2000) 1399-1407, printed in the UK, National Publication of International Patent Application No. 2001-518564 and National Publication of International Patent Application No. 2006-513553). These textured substrates are made by bonding a metal base such as stainless steel to a metal plate, i.e. textured metal layer such as a textured copper as a reinforcing material for securing handleability as a substrate.